Prismatic and diffusion inclosure.



0. A. MYGATT.

PRISMATIC AND DIFFUSION INGLOSURE.

APPLICATION FILED JULY 13, 1905.

935,220a Patented Sept. 28, 1909.

1 FIG. 4-.

[[VVE/VTOR MO 5555.- I l I 044. KM I 6% 77 M Alfomey UNITED STATES PATENT. OF ICE.-

o'rrs A. MYGATT, or NEW YORK, N. Y.

PRISMATIC AND DIFFUSION monosuan.

: Specification of Letters Patent Patented Sept. .28, 1909.

a uqatimfliea' m 13, 190 Serial No. 269,551.-

To all whom it may concern:

Be it knoWn that I, OTIS A. MYGA-T'r, a citizen of New York, residing atNew York, inthe county of New York and State of New York, have invented certain new and useful Improvements in Prismatic and Difflectors, or, shade. reflectors for' artificial fusion Inclosures, of which the following is a specification, reference beinghad therein tatheaccompanying drawing.

This invenuon, relates to shades and re ,tribution,-but an interior coating over part I character.

at least of its surface in lieu of the usual diffusing ribs. Fig; 2 is a'partial elevation and partial sectionof a reflector of like Fig; 3 is an enlarged broken section of Fi 1, showing course of some light rays. 1g. 4 is an enlarged section of a reflecting prism, Fig. 2, showing course of some light rays. I mg comparative curves of light. distribu- Fig. 5 is a diagram showtion of thev shade, Fig. 1, and the same form of shade'provlded'with internal distributing ribs instead of the translucent film.

Prism'glass globes and reflectors for diffusing and distributing light are old. In-

all cases, with one exceptlon, so far as 1 1 know, the glass is transparent, having prisms either on the inside ghnly, or on the outside, or on both sides ofthexglass. In all cases where diffusing takes place, the diffusing or softening the light 1s done by interior diffusing prisms, and the distribution of light by outer distributing surfaces, as in the Blondel and, Psaroudaki patents, Nos. 563,836, July 14, 1896, and,593,348, November 9, 1897. The material of .such prism glass as made has been invariably transparent in character (with one-exception to be mentionedhereafter) Although prism glass globes and reflectors arevery eflicient,*and-are sold .in large qu'antitiesfthere is in many cases, objection to their sparkling or brilliant, appearance;

a shade of'well-known sparkling appearance, by using a different The present invention is to do away with the medium other than prismatic surfaces in I combination with prismatic distributing surfaces@ My method of construction is, with both the reflectors and globes, to first make a globe or reflector of absolutely transparent glass, and on the outside reflecting 'or refracting prisms calculated to. reflect or re fract lightin useful directions. I then coat the inner surface of such reflectors with a translucent but not transparent. medium.

' Such a translucent but not transparent coatmg can be applied as a film on the inside and burned in, or may 'b'eapplied by blowin an o alesc'ent or opal surface on the inside of frosted .by sand blasting, or acidretchingthe inner surfaces, or any other of the current ways of rendering transparent glass trans lucent. The result of a globev or reflector made by my present method is that the rays of a light within such a globe or reflector.

pass through a translucent but not transparent surface, or medium, by which theyare diffused. They' then ass through the transparent body of the gass, and striking the dlrecting prisms on the outside are dis-' tributed in useful directions in a softened form of light. I

There are several advantages to my present method of making globes and reflectors. For instance, take a hemispherical globe (see Fig. 1). If this globe has outside horizontal deflecting prisms, calculated in the t e prism glass globe, or it may be ordinary way, by omitting the inside .vertical diifus'in prisms and covering the inside surface wit a translucent but not transparent medium, I not only succeed in softening the rays of light that pass through, but I'actually produce a globe which will give a stronger downward concentrated light than is given with a globe using insidevertical diffusing prisms. L I

In Fig. 1 a represents a shade having external distributing prisms b, and an internal film or translucent surface 0,013 the character above described. The coating 0 -'is onrittedfrom part of the shade, thus permittin light to'pass without diffusion.

In ig. 5, curve A represents ahemisphere composed entirely of transparent glass havin inside vertical dilfusingpr'isms. Curve B 15 of exactly the same external prisms, when used Wlth a smooth interior surface covr t *anspa'rent medium.

light, and sucha glohe is easier torbe kept mean. I

ered ivith a diffusing translucentbut not N t onlyan increased downward light is obtained, but a more'so ft "1 .s salts, therefore," that "reflectors so constructed have only the reflecting power due to white s' urfaces and not the comb ned reflecting powers of prisms and White surfaces. .In. my invention the. reflecting prisms are left.

untouched, the diffusing medium being ap-' plied to the opposite eurface. a

What I claim is;

,1. A transparent glass structnrehaving 35 .into inolecular' contact with 'tl1'e'glass,i1(- re .4 5. of. contact, and therefore any reflection that surfaces of prisms 7)", by which prisms the light rays are returned to the lnterior of the I reflector, -1n the usual manner With reflectlight-di'rectingprisms upon one. side and a translucent light diffusing medium upon the opposlte side,

mg prisms; but with the difference that the 1 2.. A transparent glass'strncture having 60 raysare broken up or softened, both in'p'asslight directing prisl-ns uponits exterior and lug out and returning through film v .a translucent li it diffusing medium upon.

, As I stated above, all prism'globesand itsinterioiz- -Y:

' reflectors to date'ha-ve been made oftrans- Y 3. A trz'l'nsparent glass structure; having parent glass with one exception. This ex- "light reflecting prisms uponone'eide and a 65 ception is the'Zalinski reflector, made under translucent light d'iffusingmeditlhi upon the.

Patent .No. 7755111, November 22, 1904. 'In j opposite side; i i this patent the. claims are made,' that .by: 4. A transparent glass structure haying coating" theoutside fsurfalce offa prismatic light directing prisms upon one side anda ,refiector, an increased reflectinglpower can smooth -translucentlight "diffusing medium 7 Q- .he obtained. f i i -upou the oppositef side.

' 5. A transparent glass light inelouure hay ing. lightdirecting pr sms upon 'its'exterii-n' and atranslucent"light diffusing med'iunr' 5 Thereflectingpower of prisms is heldfby" experts tobe clue wholly tolhe (Inference in -.de11sity or refractive power of the medium ,in'imn iediate contact with the prism, tl1e're-- upon. its interior. T 75 ficctlon ta king plaiceat the surfaceof chi; t). A' t anspa'rent glass liglitinclosurefliayf medium] {lhusin the oulinar prismatic 'il'lglight-1efiecti1igp1'ie111s.upon itsexterior reflector thcraysare refletiedfrom thcfsurand a translucent. lightxdi'ifusing'nredium 1 face of the air in molecular contact with the "upon ltHlllllGl'lOlZlA v v f g glassfi .lfa medium of 'approximately the ixA tral' .parcntglass light-inclosllre h m 80 "same refractive power as glass be ln'ought ing light reflectingprisms upon its exterior' and a smooth translueentlight diffusing me diam uponits interior." I; v q M S. Aglass 'inc'losure having upon a"p0r tion of its gan terior ll-ight" directing prisms and Iupon a "portion of itshinter ior a trans- .luc'ent light diffusing medium, and-having a portion" free fromlight modifying media;

in testimony whereof 'I affix my gignature in presence of two witnesses. r

' OTIS A. MYG

" llection will takeplace', This principle is. ,wellknown among opticians.- In the process .of e 1: 111'1eli1ig.aprismatic reflector,a white "o wvhitish powderis mingled with a' trans- 40j' parentli quid and applied tofthesurf'aee of the glas, the liquid being afterward ;h a rd cued in the same. nmnner; "As each liquid makes optical contact ithtlj1e-glass5 it prevents reflection taking place at the surface takes place is from the surface of the White v ROBERT K|-:L Y., Jr,

powderincorporated in the-liquid; It: re 

